Lily Allen -- Paging Dr. Luke ... Report to Gynecology, STAT! (PHOTO)

Lily Allen pulled no punches for Halloween -- taking a direct shot at Dr. Luke and the sexual assault allegations Kesha has made against him ... all in the name of her costume.

Lily was sporting scrubs and a name tag that said "Dr. Luke" from the Gynecology Dept. when she showed up at Kate Hudson's Halloween bash Thursday night in L.A.

Lily and Kesha go way back, so it's possible this is Lily's way of supporting her friend.